a = input("")
c = a.split(" ", 1)
result = []
for item in c[1]:
    if not item.isnumeric() and not item.isspace():
        num = ord(item) + int(c[0])
        if 90 < num < 97 or num > 122:
            num = num - 26
        result.append(chr(num))
    else:
        result.append(item)
print("".join(result))
